The present invention relates to a method of monitoring a pedestrian detecting device for a vehicle, wherein an absorber is provided on a bumper of the vehicle, which absorber can deform in the event of a collision with a pedestrian. The deformation is transmitted to a connecting element, and the connecting element actuates a sensor which generates a sensor signal.
A pedestrian detecting device for a vehicle is known, for example, from German Patent Document 10 2005 011 389 B4. When the bumper of a vehicle collides with a pedestrian, the bumper will be imparted and subjected to a load which deforms the bumper. This deformation is transmitted to a connecting element which actuates a sensor. The signal of this sensor can be analyzed and can be used for initiating corresponding protective measures which can reduce injury to the pedestrian.
When the vehicle is parked, a deformation of the bumper can, for example, be caused by an impact, which deformation may impair the pedestrian detecting device in its function, preventing the latter from operating properly.
There is therefore needed a method by which the operating efficiency of a pedestrian detecting device can be monitored.
According to the invention, this and other needs are met by a method of monitoring the functionality of a pedestrian detecting device for a vehicle, wherein an absorber is provided on a bumper of the vehicle, which absorber can deform in the event of a collision with a pedestrian. The deformation is transmitted to a connecting element, and the connecting element actuates a sensor which generates a sensor signal. A current sensor signal is stored as a target value every time the vehicle is parked. The current sensor signal is stored as the actual value every time the vehicle is restarted. The actual value is compared with the target value, and a deviation of the target value from the actual value is indicated.
As a result of these process steps, it becomes possible to recognize whether a deformation of the bumper has taken place during the time the vehicle was parked. On the basis of this information, the vehicle can then, for example, be checked in a service shop with respect to the functionality of the pedestrian detecting device and, if required, a repair measure can be initiated. A permanent functionality of the pedestrian detecting device is thereby ensured.
According to an advantageous embodiment, the target value and the actual value, respectively, are detected when the ignition is switched off or on. An essentially automated detection of the values therefore takes place without requiring the driver to do anything.
In order to, for example, be able to compensate temperature differences or intentional changes at the bumper, such as a change of the rigidity of the bumper by markings of different lengths, a calibration of the actual and/or target value can take place during the drive and/or when the vehicle is parked. Influences that may impair the fault recognition and are caused by the temperature and/or by changes can therefore be eliminated when the functionality of the pedestrian detecting device is checked.
Advantageously, a deviation of the actual value from the target value is indicated to the deriver visually and/or acoustically. As a result of this indication or display, the driver can then visit a service shop for checking the pedestrian detecting device.
As an alternative or in addition, a deviation of the actual value from the target value can also be stored in the fault memory of the vehicle, where it can then be read out in the service shop.
The sensor is preferably accommodated close to the outer skin of the vehicle (for example, in the interior area of a front bumper) in order to ensure an early signal detection.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of one or more preferred embodiments when considered in conjunction with the accompanying drawings.